Tian Shumei, Zhang Wenli, Shi Jinwei, Guo Zixian, Li Ming
Jiangsu Key Laboratory of Environmental Material and Environmental Engineering, College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, China.
Anal Sci. 2020 Aug 10;36(8):953-957. doi: 10.2116/analsci.19P452. Epub 2020 Feb 7.
Nanochannel plastic membranes are excellent materials for electroosmotic pump (EOP) elements owing to their surface charge properties, flexibility and cost-effectiveness. However, the surface charge properties of plastics are inferior to those of silicate-based materials. This paper reports a performance-enhanced EOP equipped with a glassified track-etch polycarbonate membrane (PC), which has a nanochannel surface covered by allylhydridopolycarbosilane (AHPCS). The effects of applied voltage, pH and membrane pore size on the electroosmotic flow velocity, along with a comparative study of the EOP with coated and pure membranes were investigated. It was found that when low DC voltage (10 - 40 V) was applied to both ends of the pump, the magnitude of the electroosmotic flow was linearly proportional to the voltage when the pore size of the membrane was less than 600 nm. A higher flow rate was obtained with larger pore size membranes. Compared with the uncoated film, the coated one showed faster electroosmosis velocity, with higher stability under the same conditions. For pH 10.0 buffer solution, a flow rate of 89.13 μL/min was obtained in the modified membrane-based EOP with excellent repeatability and durability, while the flow rate was only 37.89 μL/min in the bare PC membrane under 20 V. In order to demonstrate the performance of the developed EOP, the EOP was used for microcomplexometric titration to determine actual tap water hardness. The measured results were highly consistent with the results of a conventional complexometric titration methed. The EOP with an AHPCS-coated plastic membrane expanded the application range to harsh condition solutions, such as high-concentration acids or bases.
纳米通道塑料膜因其表面电荷特性、柔韧性和成本效益，是电渗泵（EOP）元件的优良材料。然而，塑料的表面电荷特性不如硅酸盐基材料。本文报道了一种性能增强的EOP，它配备了玻璃化径迹蚀刻聚碳酸酯膜（PC），该膜具有由烯丙基氢化聚碳硅烷（AHPCS）覆盖的纳米通道表面。研究了施加电压、pH值和膜孔径对电渗流速的影响，并对涂覆膜和纯膜的EOP进行了对比研究。结果发现，当在泵的两端施加低直流电压（10 - 40 V）时，当膜的孔径小于600 nm时，电渗流的大小与电压呈线性比例关系。孔径较大的膜获得了更高的流速。与未涂覆的膜相比，涂覆的膜显示出更快的电渗速度，在相同条件下具有更高的稳定性。对于pH 10.0的缓冲溶液，在基于改性膜的EOP中获得了89.13 μL/min的流速，具有出色的重复性和耐久性，而在20 V下，裸PC膜中的流速仅为37.89 μL/min。为了证明所开发的EOP的性能，将该EOP用于微量络合滴定以测定实际自来水硬度。测量结果与传统络合滴定方法的结果高度一致。具有AHPCS涂覆塑料膜的EOP将应用范围扩展到了苛刻条件的溶液，如高浓度的酸或碱。
